Manometric Determination of the Oxygen Diffusion Coefficients in YBa2Cu3−yFeyO6+x

Abstract

Thermodynamic parameters, such as the activation energy (Ea) and the diffusion coefficient (D0), of weakly bounded oxygen in Fe-doped YBa2Cu3O6+x (YBa2Cu3-yFeyO6+x) system were obtained utilizing the Manometric technique. It is found that under isothermal conditions, oxygen desorption in YBa2Cu3O6+x (YBCO) occurs following an exponential decay trend and in two distinct stages. During the first stage, the majority of absorbed oxygen is released, while the second stage exhibits a delayed degassing kinetics. Ea and D0 were determined for both, pressed and powdered, samples of the YBCO and YBa2Cu3-yFeyO6+x systems, from experimental kinetic curves, depicting gas release P(t) under isothermal vacuum degassing conditions. It is demonstrated that doping with Fe prevents oxygen exchange in YBCO, as evidenced by the reduction in the quantity of released oxygen with increasing iron index (y). The experimental results validate the efficacy of the Manometric method for analyzing and determining the thermodynamic and kinetic properties of the YBCO superconductor.